Former Cardiff Blues boss Dai Young is in line to rejoin the region as John Mulvihill's replacement.
Young has emerged as the favourite to take over from Mulvihill.
The Australian is set to leave the region this week after two-and-a-half years as Blues' head coach.
Young was in charge at the region between 2003 and 2011 before joining Wasps as director of rugby, where he spent almost nine years before leaving in February 2020.
Cardiff Blues are yet to officially confirm Mulvihill's departure and no deal has been completed between Young and the region.
Any initial contract could be until the end of the current season before anything longer-term is decided.
During his first stint at the Arms Park, Young won the Anglo-Welsh Cup and the Amlin Challenge Cup.
He oversaw Wasps' transition from a side who finished 11th in the Premiership to one that made three successive play-off appearances.
Young was named the Premiership's rugby director of the season in 2016-17 following Wasps' extra-time final defeat by Exeter Chiefs. He also guided Wasps to two Champions Cup semi-finals.
Dwayne Peel will join Blues' staff for the 2021-22 season.
The former Wales and British and Irish Lions scrum-half, currently at Ulster, has been appointed senior assistant coach responsible for attack.
Players were told Mulvihill was unavailable for personal reasons this week ahead of the home derby against Scarlets on 9 January.
Defence coach Richard Hodges is preparing the side for the Pro14 match this weekend.